[PATCH] crypto: cavium/nitrox - refactor deprecated strncpy

[PATCH] crypto: cavium/nitrox - refactor deprecated strncpy

[Justin Stitt]

`strncpy` is deprecated for use on NUL-terminated destination strings [1].

We know `hw.partname` is supposed to be NUL-terminated by its later use with seq_printf:
| nitrox_debugfs.c +25
|      seq_printf(s, "  Part Name: %s\n", ndev->hw.partname);

Let's prefer a more robust and less ambiguous string interface.

A suitable replacement is `strscpy` [2] due to the fact that it guarantees
NUL-termination on the destination buffer.

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2]
Link: https://github.com/KSPP/linux/issues/90
Cc: linux-hardening@vger.kernel.org
Signed-off-by: Justin Stitt <justinstitt@google.com>
---
Note: build-tested only.
---
 drivers/crypto/cavium/nitrox/nitrox_hal.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/crypto/cavium/nitrox/nitrox_hal.c b/drivers/crypto/cavium/nitrox/nitrox_hal.c
index 13b137410b75..1b5abdb6cc5e 100644
--- a/drivers/crypto/cavium/nitrox/nitrox_hal.c
+++ b/drivers/crypto/cavium/nitrox/nitrox_hal.c
@@ -647,7 +647,7 @@ void nitrox_get_hwinfo(struct nitrox_device *ndev)
 		 ndev->hw.revision_id);
 
 	/* copy partname */
-	strncpy(ndev->hw.partname, name, sizeof(ndev->hw.partname));
+	strscpy(ndev->hw.partname, name, sizeof(ndev->hw.partname));
 }
 
 void enable_pf2vf_mbox_interrupts(struct nitrox_device *ndev)

---
base-commit: 2dde18cd1d8fac735875f2e4987f11817cc0bc2c
change-id: 20230913-strncpy-drivers-crypto-cavium-nitrox-nitrox_hal-c-f6c97c7af0b4

Best regards,
--
Justin Stitt <justinstitt@google.com>

Re: [PATCH] crypto: cavium/nitrox - refactor deprecated strncpy

[Kees Cook]

On Wed, Sep 13, 2023 at 12:32:31AM +0000, Justin Stitt wrote:
> `strncpy` is deprecated for use on NUL-terminated destination strings [1].
> 
> We know `hw.partname` is supposed to be NUL-terminated by its later use with seq_printf:
> | nitrox_debugfs.c +25
> |      seq_printf(s, "  Part Name: %s\n", ndev->hw.partname);
> 
> Let's prefer a more robust and less ambiguous string interface.
> 
> A suitable replacement is `strscpy` [2] due to the fact that it guarantees
> NUL-termination on the destination buffer.
> 
> Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
> Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2]
> Link: https://github.com/KSPP/linux/issues/90
> Cc: linux-hardening@vger.kernel.org
> Signed-off-by: Justin Stitt <justinstitt@google.com>

Looks correct to me.

Reviewed-by: Kees Cook <keescook@chromium.org>

-- 
Kees Cook

Re: [PATCH] crypto: cavium/nitrox - refactor deprecated strncpy

[Herbert Xu]

On Wed, Sep 13, 2023 at 12:32:31AM +0000, Justin Stitt wrote:
> `strncpy` is deprecated for use on NUL-terminated destination strings [1].
> 
> We know `hw.partname` is supposed to be NUL-terminated by its later use with seq_printf:
> | nitrox_debugfs.c +25
> |      seq_printf(s, "  Part Name: %s\n", ndev->hw.partname);
> 
> Let's prefer a more robust and less ambiguous string interface.
> 
> A suitable replacement is `strscpy` [2] due to the fact that it guarantees
> NUL-termination on the destination buffer.
> 
> Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
> Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2]
> Link: https://github.com/KSPP/linux/issues/90
> Cc: linux-hardening@vger.kernel.org
> Signed-off-by: Justin Stitt <justinstitt@google.com>
> ---
> Note: build-tested only.
> ---
>  drivers/crypto/cavium/nitrox/nitrox_hal.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

Patch applied.  Thanks.
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt